Laparoscopic surgery is a surgical procedure in which a small incision of approximately one centimeter is made around the navel, through which an endoscope (laparoscope) and several surgical instruments are inserted to perform surgical procedures. In contrast to open abdominal surgery, laparoscopic surgery usually involves less pain, less scarring, and reduced recovery time after the operation since laparoscopic surgery only needs one or more small incisions to be made in the abdomen. Because of these advantages, the use of laparoscopic surgery as a popular diagnostic and treatment tool for a variety of diseases has increased.
Laparoscopic surgery can be directly performed with surgical instruments or be done with small robotic arms by surgeons. An example of a robot-assisted laparoscopic surgery is disclosed in Korean Patent No. 10-0585458, and the surgeon guides the movement of slave robotic arms and surgical instruments by manipulating a master robot.
During a robot-assisted laparoscopic surgery, the surgeon can perform the surgery at a console several feet away from a patient. Further, the robot-assisted laparoscopic surgery can be done in the same way the experienced surgeon does, even though the surgeon is not at the operating table.
Since the surgeons experience less physical and mental fatigue during laparoscopic surgery compared to open abdominal surgery during a surgical operation, they can as a result take care of more patients.
In laparoscopic surgery, the endoscope (laparoscope) and more than two surgical instruments are basically used. The endoscope is used to provide images of the internal organs for the surgeon to see. As the surgical instruments are special tools and devices provided for a surgical operation, grasping forceps are normally attached to the head of the instrument and are used to block blood vessels and to suture tissues.
The surgical instruments need to be made in a minimal size in order to minimize invasive damage to the body of the patient. For an accurate surgical operation of internal organs, a joint can be formed between a shaft and a head portion of the surgical instrument so that the head portion can rotate within a certain angle. An example of the surgical instrument formed with the joint is disclosed in Korean Patent No. 10-2006-0056238. In this prior art, the joint actuated by a gear is installed between the head and shaft.
In the surgical instrument having a joint actuated by a gear between the shaft and the head, there is a limit in making the diameters of the shaft and the head smaller attributable to the size of the gear. Further, there have been problems with the development and the production of the instrument because of the complicated driving means to manipulate and actuate the gear in the joint.
In laparoscopic surgery with the surgical instrument having the joint between the shaft and the head, the surgical operation can be done with minimized incisions in the abdomen. However, as the sizes of the shaft and the head become bigger due to the size of the joint, the incision needs to become bigger such that the shaft can be inserted into the patient's abdomen.
Besides, the joint actuated by the gear can rotate the head by certain degrees at regular intervals depending on the gear ratio, and thus the head cannot rotate as much as the clinician wants.
Further, only one joint actuated by the gear is not enough to rotate the head in all directions and more than two joints are needed to resolve this problem. In this case, in order to move the joints, the devices become complicated and the diameter of the shaft needs to be bigger, as a result raising the cost of manufacturing the surgical instruments.